Justin got off the R train at Whitehall Street in downtown Manhattan. After climbing one flight of stairs, he climbed three more. He stopped to catch his breath and study the city map on the station wall. It showed that the MTA Service Center was nearby on Stone Street. A sign on the station wall said, "To Stone St." He walked up two more flights of stairs. He was at a street corner, but he didn't see a sign. One block south, he saw a sign saying Bridge St. One block north, he saw a sign saying Bowling Green. Nowhere did he see a sign saying Stone St. A street vendor was selling ties at the corner. Justin asked him where Stone Street was. He said, "You're almost standing on it." He pointed up. Justin looked up—way up. About 10 feet above his head, a sign said, "Stone St."